Noise Shampoo 3.1 is an edge-preserving smoothing filter. It can be used to reduce noise on pictures, or to simplify them.

Changelog:

version 2: new algorithm variation, that leads to more photo realistic results. You can now select a separate clean strength for chroma & luminosity. Speed improvement (multithreading) , and improved memory usage.

version 3: implicitly comes with a fourth algorithm. But now algorithms are presented differently, you have instead two"quality tweaks", which leads to four combinations. The "Anti Edge Loss" setting was dropped.

Example 1: Here we applied to a picture a clean setting of 70. With the previous version of the "Vibrant surfaces" tweak (right pic), the tip of the head looks inappropriately blurred (even more than without any "quality tweak"). This kind of glitch has been fixed with the version 2, of the "Vibrant surfaces" tweak (center pic) .

Original

Vib. Surf. Version 2

Vib. Surf. Version 1

Vib. Surf. v2 + Sol. Edges

No Tweaks

Example 2: Here we applied some denoising with a "clean" setting of 60, and only the "Vibrant surfacesv2" tweak.
By default the chroma denoising strength is proportional to the main "clean" setting, with a factor of 1.5x (center pic). But this picture has too much chroma noise so we switched to a custom value of 300 (right pic).

Original

Chroma 1.5x

Chroma 300

Few notes related to controls:

Quality Tweaks: The "Vibrant Surfaces v2" tweak is the most useful, and probably should be checked all the time. Despite results look sharper with the "Solid Edges" tweak, it can be sometimes tempting to disable it. Indeed, when the "Solid Edges" tweak is disabled, surfaces look smoother and edges more regular too.

Uniform Color Space:
When this option is checked, the plugin use internally a more appropriate color space for denoising. In order to work properly, this option needs that you use sRGB as your default color profile in Photoshop.